The present invention is related to an apparatus for accurately measuring the muzzle velocity of a projectile. The present apparatus allows for improved electronic measurement of projectile muzzle velocity by effectively suppressing extraneous signals generated by gun-projectile related parameters.
Various means have been used in the prior art to measure projectile velocity. Most of these past devices measure the time interval taken for a projectile to traverse a known distance. From this information, velocity of the projectile is computed. The problem with some of these devices is that the velocity computed is the average velocity at the midpoint of the measuring device and not the actual muzzle velocity. These prior art devices have utilized velocity coils, light screens, breakwires, strain patches and pressure gages as a sensing element.
Other prior art devices use high speed photography with light or x-rays to measure the distance that the projectile travels in a known time interval. The problem with this type of measurement is that the obtained velocity is the velocity measured at the instrument and not the velocity of the projectile at the muzzle.
Micro-wave interferometry has also been used to measure projectile velocity in-bore as well as downrange from the launch weapon. The problem with microwave interferometry is that there is a severe loss of signal level at the muzzle due to ionized gases thus causing the measurement to be temporarily lost at the time of muzzle exit.